Power generation

Installed generating capacity

Installed generating capacity refers to the power generating capacity of a given facility. The energy source may be water, nuclear, conventional, solar or wind power, but installed generating capacity is usually expressed in megawatts or gigawatts.

In this type of plant, the chemical energy contained in solid, liquid or gaseous fossil fuels is converted solely to electricity using boilers and steam turbines.

Did you know ?

ENGIE is the world’s leading independent power generator, including in the Gulf states, Brazil and Thailand.

Combined-Cycle Gas & Steam Turbine (CCGT) plant

The Combined-Cycle Gas & Steam Turbine (CCGT) plant generates energy using two different types of turbine in combination: a gas turbine and a steam turbine. The hot gases generated by burning natural gas power the gas turbine. The gases are still hot enough to generate steam in a heat recovery boiler which is then used in a steam turbine. The combination of these two thermodynamic cycles increases plant efficiency to between 55% and 57%, which is much higher than the 35% to 40% achieved by traditional plants.

Cogeneration

This technique uses a single fuel to generate thermal energy (for heating and/or cooling) and electricity simultaneously. This system delivers a higher level of energy efficiency than can be achieved using separate heat and power generating facilities, and contributes to conserving energy resources. At domestic level, cogeneration boilers produce heat for space heating and domestic hot water heating, at the same time as electricity.

HVAC stands for heating, ventilation and air conditioning; three distinct technical domains that contribute to occupant comfort by treating and distributing air in all types of building, from homes to offices and industrial plants. It also covers all the specialty skills and specialist technicians involved in heating, ventilation and air conditioning.

Unavoidable energy

No energy conversion process can ever achieve 100% efficiency. The term ‘unavoidable energy’ refers to the quantity of energy inevitably present or trapped in certain processes, uncontrolled energy flows or materials. A proportion of this energy can be recovered and/or reclaimed. This term also applies to energy that would be lost if it were not used at the moment it is available, such as electricity generated from intermittent sources like wind power, solar power and run-of-river hydropower.

Renewables are naturally occurring sources of energy that involve little or no waste or polluting emissions. These energy sources are either inexhaustible or can be rapidly regenerated by human intervention. Electrical power generated from renewables is referred to as ‘green power’.

Hydropower

Hydropower is a renewable energy source that harnesses the energy of moving water.

Joule (J)

The joule is a derived unit of energy in the SI International system of units, and is used to measure energy (for work done) and the quantity of energy dissipated as heat. In the context of electrical power, one joule is the energy required to produce 1 watt of power for one second, or the energy transferred to an object when a force of 1 newton acts on that object in the direction of its motion through a distance of 1 meter. In terms of electricity and thermal energy, the most commonly used unit is the kilowatt hour (1 kWh = 3,600 kJ).

Kerosene

A fractional distillate of petroleum of quality between gasoline and diesel oil. At least 65% of its volume must be distilled at a temperature below 250°C. Its relative density is approximately 0.80 g/m3 and its flash point range begins at 38°C. Kerosene is used for heating and lighting, but may also be used as a fuel for some types of internal combustion engine.

Kilowatt (kW)

The watt (W) is a derived unit of power in the SI International system of units, and is used to measure electrical power. One watt is defined as the power of one joule per second. The two most commonly used units refer to multiples of the watt: the kilowatt (kW), and for highly rated power generating plants the megawatt (MW).

Did you know ?

The power rating of a domestic electric kettle is between 1 and 2 kW.

Kilowatt hour (kWh)

This is the unit used to measure the quantity of energy transmitted over a given period of time. One kWh is equivalent to 3,600 kJ or 3.6 MJ, or the quantity of energy used in one hour by an electrical appliance rated at 1,000 watts.

Did you know ?

A family of four consumes around 7,000 kilowatt hours of electricity every year, excluding heating.

1 kilowatt hour = 1,000 Watts per hour

1 megawatt hour = 1,000 kW per hour

1 gigawatt hour = 1 million kW per hour

1 terawatt hour = 1,000 GWh

Nuclear

Nuclear energy is the energy contained in the nucleus of an atom to maintain cohesion between neutrons and protons. That energy can be extracted by triggering a nuclear chain reaction in which heavy atoms like uranium are split (in a fission reaction), or light atoms like hydrogen are combined (in a fusion reaction). During these nuclear reactions, the atoms lose a little of their mass in the form of a large amount of thermal energy, which is used as a heat source to generate electricity.

Offshore

A subsea oil drilling facility located on a production platform above the sea.

Oil pipeline

A pipeline – usually below ground – used to carry pumped oil.

Oil

Natural mineral oil accumulated in oil deposits and extracted as a source of energy.

Crude oil

A mixture of hydrocarbons in varying proportions in liquid state under natural conditions, found in deposits with differing conditions of pressure and temperature. Crude oil may contain small quantities of materials other than hydrocarbons.

Fuel celle

A new process enabling the generation of power and heat with a high level of electrical efficiency and a lower level of environmental impact (no noise pollution or emissions of polluting gases, such as carbon monoxide, nitrogen oxides, soot or other particulates). The direct conversion of the chemical energy contained in the fuel into electrical energy lies at the heart of this process.

Production platform

All the above-sea installations required to extract oil and gas from subsea deposits.

Heat pump

A device enabling calories to be extracted from the external environment (calories in air, water or soil) to heat the inside of a building (heating mode), or to remove calories from a building to the external environment (air conditioning mode).

Power rating

The maximum amount of energy output for a given appliance. It is expressed in kilowatts (kW).

Calorific value

Quotient of the quantity of heat provided over a given period of time.

Energy efficiency ratio

In physics and mechanics, the energy efficiency ratio refers to the ratio between work provided and the quality of energy required to obtain it. It ranges from 0 to 100%.

Ditrict heating network

The district heating network is a system that distributes heat generated centrally to serve multiple users. It comprises one or more heat generating plants, a primary distribution network and heat exchanger substations.

Casing

All the tubular steel components installed in a drilled well to extract natural resources.